Physical Layer: Transmission Media, Encoding, and Modulation Techniques

Question 1

What is the primary purpose of a network interface card (NIC)?

Accepted Answer

To facilitate data transfer between a device and a network

Answer

To encode data for transmission

Answer

To modulate data signals

Answer

To provide security for data transmissions

Question 2

Which modulation technique is commonly employed for data transmission over fiber optic cables?

Accepted Answer

Phase Shift Keying (PSK)

Answer

Amplitude Modulation (AM)

Answer

Frequency Modulation (FM)

Answer

Quadrature Amplitude Modulation (QAM)

Question 3

What is the primary function of a modem in data communication?

Accepted Answer

To convert digital signals into analog signals

Answer

To convert analog signals into digital signals

Answer

To amplify data signals

Answer

To filter out noise from data signals

Question 4

What is the primary responsibility of the physical layer in the Open Systems Interconnection (OSI) model?

Accepted Answer

Defining the transmission media and data representation

Answer

Providing error detection and correction

Answer

Establishing routing and addressing

Answer

Handling data encryption and decryption

Question 5

Which type of fiber optic cable is optimized for transmitting data over long distances?

Accepted Answer

Single-mode fiber

Answer

Multimode fiber

Answer

Plastic optical fiber

Answer

Graded-index fiber

Question 6

What is the fundamental difference between synchronous and asynchronous data transmission?

Accepted Answer

Synchronous transmission employs a clock to synchronize data flow, while asynchronous transmission does not.

Answer

Asynchronous transmission employs a clock to synchronize data flow, while synchronous transmission does not.

Answer

Synchronous transmission is inherently faster than asynchronous transmission.

Answer

Asynchronous transmission is inherently more reliable than synchronous transmission.

Question 7

Which of the following is NOT a physical transmission medium used in data communication networks?

Accepted Answer

Infrared

Answer

Twisted pair

Answer

Fiber optic cable

Answer

Coaxial cable

Question 8

Which network technology, utilizing fiber optic cables, employs multiplexed wavelengths of light to attain exceptionally high data rates of up to 100 Gbps?

Accepted Answer

Fiber optic cable with Dense Wavelength Division Multiplexing (DWDM)

Answer

Ethernet

Answer

Coaxial cable

Answer

Twisted pair cable

Question 9

Which of the following is NOT a physical transmission medium commonly used in data communication networks?

Accepted Answer

Transistor

Answer

Twisted pair cable

Answer

Coaxial cable

Answer

Fiber optic cable

Question 10

What is the primary function of a network interface card (NIC) in a computer system?

Accepted Answer

Provide a physical connection to a network

Answer

Convert data into digital signals

Answer

Encrypt data before transmission

Answer

Store network configuration settings

Question 11

Which modulation technique, among the following, is employed to encode digital data onto an analog carrier signal by varying the phase of the carrier?

Accepted Answer

Phase Shift Keying (PSK)

Answer

Amplitude Shift Keying (ASK)

Answer

Frequency Shift Keying (FSK)

Answer

Quadrature Amplitude Modulation (QAM)

Question 12

Which modulation scheme, among the following options, utilizes phase shifts to represent binary data?

Accepted Answer

Phase Shift Keying (PSK)

Answer

Amplitude Shift Keying (ASK)

Answer

Frequency Shift Keying (FSK)

Answer

Quadrature Amplitude Modulation (QAM)

Question 13

Which of the following protocols is commonly used at the physical layer of the TCP/IP protocol suite?

Accepted Answer

Point-to-Point Protocol (PPP)

Answer

Transmission Control Protocol (TCP)

Answer

User Datagram Protocol (UDP)

Answer

Hypertext Transfer Protocol (HTTP)

Question 14

What is the primary function of a modem in data communication systems?

Accepted Answer

Convert digital signals to analog signals

Answer

Convert analog signals to digital signals

Answer

Amplify signals to increase their transmission range

Answer

Filter out noise and interference from signals

Question 15

Which of the following accurately describes the primary purpose of a network interface card (NIC)?

Accepted Answer

Interfacing a computer with a network

Answer

Encoding digital signals into analog format

Answer

Amplifying data transmissions

Answer

Encrypting data for secure communication

Question 16

Indicate the modulation technique employed to transmit data across telephone lines:

Accepted Answer

Amplitude modulation (AM)

Answer

Frequency modulation (FM)

Answer

Phase modulation (PM)

Answer

Quadrature amplitude modulation (QAM)

Question 17

Specify the objective of Manchester encoding:

Accepted Answer

Ensuring transitions between bits

Answer

Minimizing bandwidth consumption

Answer

Improving signal-to-noise ratio

Answer

Detecting transmission errors

Question 18

Discriminate between synchronous and asynchronous transmission based on their use of a clock signal:

Accepted Answer

Synchronous transmission uses a clock, while asynchronous transmission does not.

Answer

Asynchronous transmission uses a clock, while synchronous transmission does not.

Answer

Both synchronous and asynchronous transmission use a clock.

Answer

Neither synchronous nor asynchronous transmission uses a clock.

Question 19

Determine the maximum data transfer rate supported by 100Base-T Ethernet:

Accepted Answer

100 Mbps

Answer

10 Mbps

Answer

1 Gbps

Answer

10 Gbps

Question 20

Which technique is NOT employed to mitigate the impact of noise in data transmission?

Accepted Answer

Data compression

Answer

Error detection

Answer

Error correction

Answer

Forward error correction

Question 21

What is a primary advantage of multiplexing in data communication?

Accepted Answer

Allows multiple signals to be transmitted simultaneously over a single channel.

Answer

Eliminates the need for error correction mechanisms.

Answer

Significantly reduces the cost of data transmission.

Answer

Simplifies the design of data communication networks.

Question 22

Which of the following statements accurately compares wired and wireless transmission media?

Accepted Answer

Wired media typically offers higher bandwidth and lower latency than wireless media.

Accepted Answer

Wireless media is more susceptible to interference and signal degradation compared to wired media.

Accepted Answer

Wired media is generally more expensive and less flexible to install than wireless media.

Answer

Wireless media provides enhanced security compared to wired media.

Question 23

In a noisy channel with restricted bandwidth, which modulation technique is most suitable? Explain your reasoning.

Accepted Answer

BPSK (Binary Phase Shift Keying)

Answer

QPSK (Quadrature Phase Shift Keying)

Answer

16-QAM (16-Quadrature Amplitude Modulation)

Answer

8-PSK (8-Phase Shift Keying)

Question 24

Which of the following is NOT a type of transmission medium in data communication?

Accepted Answer

Cellular data

Answer

Coaxial cable

Answer

Optical fiber

Answer

Twisted pair

Question 25

What is the primary purpose of a Network Interface Card (NIC)?

Accepted Answer

To connect a device to a network

Answer

To encode data into signals

Answer

To modulate data onto a carrier wave

Answer

To amplify signals before transmission

Question 26

Which modulation technique converts digital data into a continuous wave with varying amplitude?

Accepted Answer

Amplitude Modulation (AM)

Answer

Frequency Modulation (FM)

Answer

Phase Modulation (PM)

Answer

Quadrature Amplitude Modulation (QAM)

Question 27

Which of the following best describes the difference between synchronous and asynchronous data transmission?

Accepted Answer

Synchronous transmission uses fixed time slots, while asynchronous does not

Answer

Asynchronous transmission uses fixed time slots, while synchronous does not

Answer

Synchronous transmission is typically faster than asynchronous

Answer

Asynchronous transmission is typically faster than synchronous

Question 28

What is the primary purpose of data encoding in the Physical Layer?

Accepted Answer

To represent digital data in a form suitable for transmission

Answer

To increase the transmission speed

Answer

To reduce errors in transmission

Answer

To provide encryption for data security

Question 29

Which IEEE standard defines the Physical Layer specifications for Ethernet networks?

Accepted Answer

IEEE 802.3

Answer

IEEE 802.11

Answer

IEEE 802.15

Answer

IEEE 802.16

Question 30

Which of the following is NOT a type of guided transmission medium?

Accepted Answer

Infrared

Answer

Coaxial cable

Answer

Fiber optic cable

Answer

Twisted pair cable

Question 31

What is the primary purpose of a network interface card (NIC)?

Accepted Answer

To facilitate data transfer between a computer and a network

Answer

To decode data received from the network

Answer

To encrypt data for secure transmission

Answer

To amplify data signals for long-distance transmission

Question 32

Which type of modem is used to convert digital signals to analog signals for transmission over analog telephone lines?

Accepted Answer

Analog modem

Answer

Fiber optic modem

Answer

Cable modem

Answer

DSL modem

Question 33

What is the main purpose of data encoding in the physical layer?

Accepted Answer

To represent digital data in a form suitable for transmission over a specific medium

Answer

To reduce data transmission errors

Answer

To increase data transmission speed

Question 34

Which modulation technique is commonly used to transmit data over analog telephone lines?

Accepted Answer

Amplitude modulation (AM)

Answer

Phase modulation (PM)

Answer

Frequency modulation (FM)

Answer

Quadrature amplitude modulation (QAM)

Question 35

Which factor primarily influences the bandwidth of a transmission medium?

Accepted Answer

Conductor material properties

Answer

Cable length

Answer

Signal strength

Answer

Environmental noise

Question 36

What is the function of a splitter in a fiber optic network?

Accepted Answer

To divide an optical signal into multiple signals for distribution to different network devices

Answer

To combine multiple optical signals into one signal for transmission

Answer

To amplify optical signals for long-distance transmission

Answer

To filter out unwanted optical signals

Question 37

Which of the following is an advantage of using shielded twisted pair (STP) cable over unshielded twisted pair (UTP) cable?

Accepted Answer

Improved resistance to electromagnetic interference (EMI)

Answer

Increased cable flexibility

Answer

Higher data transmission speeds

Answer

Lower cost

Question 38

What is the primary function of a network interface card (NIC)?

Accepted Answer

Connects a device to a network

Answer

Encodes data into electrical signals

Answer

Provides security for data transmission

Answer

Modulates data onto a carrier wave

Question 39

What is the main purpose of data encoding in the physical layer?

Accepted Answer

To convert digital data into a form suitable for transmission

Answer

To encrypt data for security

Answer

To compress data to reduce transmission time

Question 40

What is the role of a repeater in a physical layer network?

Accepted Answer

Amplifies and retransmits signals to extend the transmission distance

Answer

Provides error correction for data transmission

Answer

Converts signals from one transmission medium to another

Question 41

Which of the following is a characteristic of twisted-pair cable?

Accepted Answer

Consists of two insulated copper wires twisted together

Answer

Has a higher bandwidth than coaxial cable

Answer

Transmits data using optical fibers

Question 42

What do we call the area in a network where data collisions can occur?

Accepted Answer

Collision domain

Answer

Broadcast domain

Answer

Security domain

Question 43

Which of the following is NOT an advantage of using fiber optic cable as a transmission medium?

Accepted Answer

Susceptible to electromagnetic interference

Answer

Low signal loss

Answer

High bandwidth

Answer

Lightweight and flexible

Question 44

What is the purpose of a data rate in the physical layer?

Accepted Answer

To measure the speed at which data is transmitted

Answer

To control the flow of data in a network

Answer

To ensure the integrity of transmitted data

Answer

To determine the type of modulation used

Question 45

Which of the following is a common type of transmission media used in the Physical Layer of data communication networks?

Accepted Answer

Twisted-pair cable

Answer

SQL database

Answer

Cloud storage

Answer

Excel spreadsheet

Question 46

What is the primary purpose of a network interface card (NIC)?

Accepted Answer

To connect a device to a computer network

Answer

To amplify and regenerate signals over long distances

Answer

To convert analog signals to digital signals

Question 47

What is the main purpose of data encoding in the Physical Layer?

Accepted Answer

To represent digital data as physical signals for transmission

Answer

To compress data for efficient transmission

Answer

To enhance the signal-to-noise ratio

Answer

To encrypt data for secure transmission

Question 48

Which type of modem is commonly used for high-speed internet access over telephone lines?

Accepted Answer

DSL modem

Answer

Fiber-optic modem

Answer

Analog modem

Answer

Cable modem

Question 49

What is the key difference between baseband and broadband transmission in the Physical Layer?

Accepted Answer

Baseband transmits digital signals without modulation, while broadband transmits modulated signals.

Answer

Baseband uses a lower frequency than broadband

Answer

Broadband supports multiple channels, while baseband does not.

Question 50

Which factor primarily affects the maximum data rate of a transmission channel?

Accepted Answer

Bandwidth

Answer

Latency

Answer

Jitter

Answer

Packet loss

Question 51

What is the primary function of the Physical Layer in the TCP/IP model?

Accepted Answer

To provide the physical connection between devices and transmit data bits

Answer

To ensure reliable data delivery

Answer

To manage network addresses

Question 52

Which characteristic is a key advantage of fiber-optic cables for data transmission?

Accepted Answer

Extremely high bandwidth and low signal attenuation

Answer

Resistance to electromagnetic interference

Answer

Low cost and ease of installation

Answer

Short transmission distances and high error rates

Question 53

What is the purpose of a repeater in a network?

Accepted Answer

To amplify and regenerate signals over extended distances

Answer

To provide a secure connection between devices

Answer

To connect devices with different network interfaces